Effects of dietary energy and methionine on growth performance and carcass traits of growing Pekin ducks from 15 to 42 days of age

Mannanase improves the growth performance of broilers by alleviating inflammation of the intestinal epithelium and improving intestinal microbiota

This experiment aimed to discuss and reveal the effect and mechanism of mannanase on intestinal inflammation in broilers triggered by a soybean meal diet. In this experiment, 384 Arbor Acres broilers at 1 d old were randomly divided into 3 treatment groups. The broilers were fed a corn-soybean meal basal diet, a low-energy diet (metabolizable energy reduced by 50 kcal/kg), and a low-energy diet supplemented with 100 mg/kg mannanase for 42 d. The low-energy diet increased feed conversion ratio from 0 to 42 d, reduced ileal villus height and villus height-to-crypt depth ratio and upregulated the expression of nuclear factor kappa B (NF-κB) in the ileum (P < 0.05). It also reduced cecal short-chain fatty acids (SCFA), such as acetic acid (P < 0.05). Compared with low-energy diets, the addition of mannanase increased body weight at 42 d, promoted the digestibility of nutrients, and maintained the morphology and integrity of the intestinal epithelium of broilers (P < 0.05). In addition, mannanase upregulated the expression of claudin-1 (CLDN1) and zonula occludens-1 (ZO-1) in the jejunum at 21 d, downregulated the expression of ileal NF-κB, and increased the content of isobutyric acid in the cecum of broilers (P < 0.05). The results for the ileal microbiota showed that a low-energy diet led to a decrease in the relative abundance of Lactobacillus reuteri in the ileum of broilers. The addition of mannanase increased the relative abundance of Lactobacillus-KC45b and Lactobacillus johnsonii in broilers. Furthermore, a low-energy diet reduced the relative abundance of Butyricicoccus in the intestine of broilers and inhibited oxidative phosphorylation and phosphoinositol metabolism. Mannanase increased the relative abundance of Odoribacter, promoted energy metabolism and N-glycan biosynthesis, and increased the activities of GH3 and GH18. It is concluded that mannanase could improve the growth performance of broilers by reducing the expression of NF-κB in the ileum, increasing the production of SCFA in the cecum, suppressing intestinal inflammation, balancing the intestinal microbiota, reducing damage to the intestinal barrier, and improving the efficiency of nutrient utilization to alleviate the adverse effects caused by the decrease in dietary energy level.

The apparent metabolisable energy requirement of Sansui ducks from hatch to 21 days of age

A dose-response experiment was conducted to estimate optimal dietary apparent metabolisable energy requirement (AME) in Sansui ducks (Sansui Sheldrake duck) from hatch to 21 days of age. Three hundred thirty-six one-day-old male Sansui ducks were randomly assigned to six experimental treatments, each consisting of seven replicate pens with eight birds per pen. Birds were fed diets containing either 10.92, 11.38, 11.8, 12.26, 12.68 and 13.14 MJ AME/kg, respectively. At 21 d of age, the body weight, weight gain, feed intake, protein intake, energy intake and feed conversion ratio of ducklings from each pen were measured. Increasing AME content from 10.92 MJ/kg to 13.14 MJ/kg significantly improved body weight, weight gain, feed intake, feed conversion ratio and crude protein intake (P<0.05). No significant changes in energy intake were found among treatments (P>0.05). Based on broken-line regression analysis, the AME requirement of male Sansui ducks from hatch to 21 d of age was 11.49 and 11.59 MJ/kg for maximum body weight and best feed conversion ratio, respectively.

Dietary methionine deficiency stunts growth and increases fat deposition via suppression of fatty acids transportation and hepatic catabolism in Pekin ducks

Background

Although methionine (Met), the first-limiting dietary amino acid, has crucial roles in growth and regulation of lipid metabolism in ducks, mechanisms underlying are not well understood. Therefore, the objective was to use dietary Met deficiency to investigate the involvement of Met in lipid metabolism and fat accumulation of Pekin ducks.

Methods

A total of 150 male Pekin ducks (15-d-old, 558.5 ± 4.4 g) were allocated into 5 groups (6 replicates with 5 birds each) and fed corn and soybean meal-based diets containing 0.28%, 0.35%, 0.43%, 0.50%, and 0.58% Met, respectively, for 4 weeks. Met-deficient (Met-D, 0.28% Met) and Met-adequate (Met-A, 0.43% Met) groups were selected for subsequent molecular studies. Serum, liver, and abdominal fat samples were collected to assess the genes and proteins involved in lipid metabolism of Pekin ducks and hepatocytes were cultured in vivo for verification.

Results

Dietary Met deficiency caused growth depression and excess fat deposition that were ameliorated by feeding diets with adequate Met. Serum triglyceride and non-esterified fatty acid concentrations increased (P < 0.05), whereas serum concentrations of total cholesterol, low density lipoprotein cholesterol, total protein, and albumin decreased (P < 0.05) in Met-D ducks compared to those in Met-A ducks. Based on hepatic proteomics analyses, dietary Met deficiency suppressed expression of key proteins related to fatty acid transport, fatty acid oxidation, tricarboxylic acid cycle, glycolysis/gluconeogenesis, ketogenesis, and electron transport chain; selected key proteins had similar expression patterns verified by qRT-PCR and Western blotting, which indicated these processes were likely impaired. In vitro verification with hepatocyte models confirmed albumin expression was diminished by Met deficiency. Additionally, in abdominal fat, dietary Met deficiency increased adipocyte diameter and area (P < 0.05), and down-regulated (P < 0.05) of lipolytic genes and proteins, suggesting Met deficiency may suppress lipolysis in adipocyte.

Conclusion

Taken together, these data demonstrated that dietary Met deficiency in Pekin ducks resulted in stunted growth and excess fat deposition, which may be related to suppression of fatty acids transportation and hepatic catabolism.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00709-z.

Effect of Dietary L-Methionine Supplementation on Growth Performance, Carcass Traits, and Plasma Parameters of Starter Pekin Ducks at Different Dietary Energy Levels

Simple Summary

Tremendous improvements have been made in the duck commercial industry, especially in aspects such as the increase of body weight and shortening of the production cycle. Meat duck production has been increasing annually worldwide. Improvements in precise nutrition were crucial for ducks to improve growth efficiency and reduce diet costs. Currently, L-Met, a new methionine (Met) source, has been commercially available for duck diet formulation. The bioavailability of L-Met is greater than DL-Met for growth performance in duck. The present study estimated the Met requirement of starter Pekin ducks from 1 to 21 days of age by supplementing crystal L-Met to formulate the diets at different ME levels. The results suggested that the Met requirement of starter Pekin ducks was affected by dietary ME levels. The data potentially provide theoretical support for the utilization of crystalline L-Met in duck production.

Abstract

A 2 × 6 factorial experiment was conducted to determine the influences of dietary metabolizable energy (ME) and methionine (Met) levels on growth performance, carcass traits, and plasma biochemical parameters of starter Pekin ducks from 1 to 21 days of age. A total of 600 one-day-old male Pekin ducklings were randomly assigned to 12 groups (six replicates each group and eight ducks per replicate) in a 2 × 6 two-factor arrangement. The basal Met levels of two basal diets (11.54 and 12.52 MJ/kg ME) were 0.31 and 0.29%, respectively. The crystalline L-Met was supplemented to yield six diets according to different supplemental levels (0, 0.05, 0.10, 0.15, 0.20, and 0.25%). The results showed that the body weight (BW) and average daily weight gain (ADG) were increased (p < 0.05) with increasing dietary Met levels. Dietary ME levels changed from 11.54 to 12.52 MJ/kg increased the BW and ADG (p < 0.05) as well as decreased the average daily feed intake and feed to gain ratio (p < 0.05). As the dietary Met level increased, leg muscle yield increased (p < 0.05). Conversely, increasing the dietary ME level decreased the leg muscle yield (p = 0.0024) and increased abdominal fat (p < 0.001). Meanwhile, the concentrations of total cholesterol (TCHO), high-density lipoprotein cholesterol (HDLC), and low-density lipoprotein cholesterol (LDLC) in plasma were decreased (p < 0.05) when the ME levels of diets changed from 11.54 to 12.52 MJ/kg. Meanwhile, the plasma TCHO and HDLC concentrations decreased (p < 0.05) as dietary Met levels increased. Based on the linear-broken line model, the dietary Met requirement of starter Pekin ducks from 1 to 21 days of age for optimal ADG were 0.362% (0.052% supplemental L-Met) at 11.54 MJ ME/kg and 0.468% (0.178% supplemental L-Met) at 12.52 MJ ME/kg, respectively, when crystal L-Met was supplemented to formulate the diets. This suggested that the Met requirement of starter Pekin ducks was affected by dietary ME levels. The data potentially provide theoretical support for the utilization of crystalline L-Met in duck production.